Fluid used in large scale air conditioning and related applications, typically a liquid and gas mixture of water and air, is often treated or scrubbed to clean it. This treatment can include filtering, humidifying and cooling the fluid.
One system for such treatment of air in mine ventilation, directs a spray of chilled water at rotating fan blades, which blades drive the air for use in ventilation. The water impacts the blades and cools the air by contact. The system requires sophisticated waterproofing of the fan drive and also results in rapid wear of the blades.
The use of a thrown fluid movement for pumping fluid is known, and one example is described in U.S. Pat. No. 2,911,137 to M. L. Edwards. Edwards utilises a rotary impeller in a primed sump to draw fluid through a hollow shaft, and discharge it radially to drive the fluid. The pumping fluid and the driven fluid are usually not the same and the essence of the pumping action is that the fluids mix at low relative velocities and pumping energy.
Another kind of impeller is known in use with a vacuum pump, and is described in U.S. Pat. No. 2,633,290 to Schaefer. et al. In the Schaefer device, a pair of rotating spiral tubes within a vessel are used to draw water from a sump at the vessel bottom, and throw the water radially outwardly at the vessel top, to draw air out of the vessel and create a vacuum therein.